Logic puzzle game is one of popular games that falls into Constraint Satisfaction Problem (CSP). Solving the puzzle needs logic and reasoning. Based on given hypotheses, it could come out by more that one soluction. When the set of hypotheses is not lead to the conclusion, then the introduction of assumption is required. Solving This logic problem using pen and paper is common is practice, but due to the limitation of human brain one may and up with unexpected solution. Particulaly for those who wants to seek the solucation in a systematic way, then the presence of a tool that really help them understand the strategy better is unquestionable. This report presents a thorough discussion on “Lotrix”, an application for solving the logic problems. Supported by backtracking to explore further possibilities when contradiction detected, the software is designed to be a solving tool and further expected to have the capability to solve all the logic grid puzzle at any difficulty level. A series of test perfomed using easy, medium, and hard level problem set indicates q 100% success rate. Keyword : logic grid puzzle, inference